Spray systems which are used for this application, are identical to those used for insulating roofs from the inside. Application of this type of foams, require very fast reaction times of the system used. Foam is sprayed with a high pressure machine. It is applied as a fluid film after which the foam process starts within 2 seconds. Because the produced fluid film follows the contours of the subsoil totally, a very high insulation value is obtained. No cold bridges are left. The reacted fluid, the cured PUR foam, follows and wraps the trusses and all other parts of the construction. In both housing and utility sector this type of foam is used. When constructing houses, the inner skin of the brick or block work may be sprayed. This leaves the possibility of applying wall ties afterwards. In the utility sector, another usage of the building may be required. Buildings that are no insulated yet, can easily be upgraded with an added value like an insulating spray foam. This frequently occurs when buildings change its ownership. The huge advantage of a spray foam is that there is no mechanical mounting and fixing needed which would be the case when applying insulating boards.